Implications for practice
The evidence from the prospective cohort trials is considered to be too weak to be able to draw a definite conclusion about the preventive effect of whole grain foods on the development of type 2 diabetes.
1
Implications for research
Properly designed long-term randomised controlled trials are needed to
establish whether whole grain foods are protective for the development of type 2 diabetes. To facilitate this, further mechanistic research should focus on finding a set of relevant intermediate endpoints for type 2 diabetes and on identifying genetic subgroups of the population at risk that are most susceptible to dietary intervention.
Acknowledgements
We thank prof. Mark Pereira and prof. June Stevens for providing additional data on their studies. We are grateful to prof. Ronald Stolk for advice on the final review.
This paper has been written with financial support from the Commission of the European Communities, specific rtd programme “Quality of Life and Management of Living Resources”, qlk 1-2001-00431 “Stable isotope applications to monitor starch digestion and fermentation for the development of functional foods” (www.eurostarch.org). It does not necessarily reflect its views and in no way anticipates the Commission’s future policy in this area.
References
American Diabetic Association, Report of the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus. Diabetes Care 1999;22 (Suppl 1):s5–19.
American Diabetic Association. Report of the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus. Diabetes Care 1997;20:1183–97.
Bakker SJ, Hoogeveen EK, Nijpels G, Kostense PJ, Dekker JM, Gans RO, et al. The association of dietary fibres with glucose tolerance is partly explained by concomitant intake of thiamine: the Hoorn Study. Diabetologia 1998;41(10):1168–75.
Burkitt D. Refined carbohydrate foods and disease: some implications of dietary fiber.
London: Academic Press, 1975.
Cohen J. A coefficient of agreement for nominal scales. Educational and Psychological Measurement 1960;20:37–46.
Dam van R, Hu FB, Rosenberg L, Krishnan S, Palmer JR. Dietary Calcium and Magnesium, Major Food Sources, and Risk of type 2 Diabetes in U.S. Black Women. Diabetes Care 2006;29 (10):2238–43.
Dandona P, Aljada A, Bandyopadhyay A. Inflammation: the link between insulin resistance, obesity and diabetes. Trends in Immunology 2004;25(1):4–7.
Egger M, Davey Smith G, Schneider M, Minder C. Bias in meta-analysis detected by a simple, graphical test. British Medical Journal 1997;315(7109):629–34.
Feskens EJ, Bowles CH, Kromhout D. Carbohydrate intake and body mass index in relation to the risk of glucose intolerance in an elderly population. American Journal of Clinical Nutrition 1991;54 (1):136–40.
Food and Agriculture Organization of the United Nations. Carbohydrates in human nutrition: report of a Joint fao/who Expert consultation. Nutrition Paper no. 66.
Rome: fao, 1998.
Food and Agriculture Organization of the United Nations/World Health Organization.
Diet, nutrition and prevention of chronic disease: Report of a Joint who/fao Expert consultation. Geneva: World Health Organisation, 2003.
Fung TT, Hu FB, Pereira MA, Liu S, Stampfer MJ, Colditz GA, et al. Whole-grain intake and the risk of type 2 diabetes: a prospective study in men. American Journal of Clinical Nutrition 2002;76(3): 535–40.
Higgins JP, Thompson SG, Deeks JJ, Altman DG. Measuring inconsistency in meta-analyses. British Medical Journal 200;21:557–60.
Higgins JPT, Green S, editors. Cochrane Handbook for Systematic Reviews of Interventions 4.2.5 [updated May 2005]. In: The Cochrane Library, Issue 3, 2005.
Chichester, uk: John Wiley & Sons, Ltd.
Hodge AM, Montgomery J, Dowse GK, Mavo B, Watt T, Zimmet PZ. A case-control study of diet in newly diagnosed niddm in the Wanigela people of Papua New Guinea.
Diabetes Care 1996;19(5): 457–62.
Jacobs DR, Jr, Meyer KA, Kushi LH, Folsom AR. Whole-grain intake may reduce the risk of ischemic heart disease death in postmenopausal women: the Iowa Women’s Health Study. American Journal of Clinical Nutrition 1998;68(2):248–57.
Jadad AR, Moore RA, Carroll D, Jenkinson C, Reynolds DJ, Gavaghan DJ. Assessing the quality of reports of randomized clinical trials: Is blinding necessary? Controlled Clinical Trials 1996;17:1–12.
Juntunen KS, Laaksonen DE, Poutanen KS, Niskanen LK, Mykkanen HM. High-fiber rye bread and insulin secretion and sensitivity in healthy postmenopausal women.
American Journal of Clinical Nutrition 2003;77(2):385–91.
Koh-Banerjee P, Franz M, Sampson L, Liu S, Jacobs DR, Jr., Spiegelman D, et al. Changes in whole-grain, bran, and cereal fiber consumption in relation to 8-y weight gain among men. American Journal of Clinical Nutrition 2004;80(5):1237–45.
1
Koh-Banerjee P, Rimm EB. Whole grain consumption and weight gain: a review of the epidemiological evidence, potential mechanisms and opportunities for future research.
Proceedings of the Nutrition Society 2003;62(1):25–9.
Lau J, Ioannidis JP, Terrin N, Schmid CH, Olkin I. The case of the misleading funnel plot.
British Medical Journal 2006;333:597–600.
Liese AD, Roach AK, Sparks KC, Marquart L, D’Agostino RB, Jr, Mayer-Davis EJ. Whole-grain intake and insulin sensitivity: the Insulin Resistance Atherosclerosis Study.
American Journal of Clinical Nutrition 2003;78(5):965–71.
Liu S, Manson JE, Stampfer MJ, Hu FB, Giovannucci E, Colditz GA, et al. A prospective study of whole-grain intake and risk of type2 diabetes mellitus in us women. American Journal of Public Health 2000;90(9):1409–15.
Liu S, Stampfer MJ, Hu FB, Giovannucci E, Rimm E, Manson JE, et al. Whole-grain consumption and risk of coronary heart disease: results from the Nurses’ Health Study.
American Journal of Clinical Nutrition 1999;70:412–9.
Liu S. Intake of refined carbohydrates and whole grain foods in relation to risk of type 2 diabetes mellitus and coronary heart disease. Journal of the American College of Nutrition 2002;21:298–306
Liu S. Whole-grain foods, dietary fiber, and type 2 diabetes: searching for a kernel of truth.
American Journal of Clinical Nutrition 2003;77 (3):527–9.
Ludwig DS. The glycemic index: physiological mechanisms relating to obesity, diabetes, and cardiovascular disease. Journal of the American Medical Association 2002;287(18):2414–23.
Marshall JA, Weiss NS, Hamman RF. The role of dietary fiber in the etiology of non-insulin-dependent diabetes mellitus. The San Luis Valley Diabetes Study. Annals of Epidemiology 1993;3(1):18–26.
McKeown NM, Meigs JB, Liu S, Saltzman E, Wilson PW, Jacques PF. Carbohydrate nutrition, insulin resistance, and the prevalence of the metabolic syndrome in the Framingham Offspring Cohort. Diabetes Care 2004;27(2):538–46.
McKeown NM, Meigs JB, Liu S, Wilson PW, Jacques PF. Whole-grain intake is favorably associated with metabolic risk factors for type 2 diabetes and cardiovascular
disease in the Framingham Offspring Study. American Journal of Clinical Nutrition 2002;76(2):390–8.
Meyer KA, Kushi LH, Jacobs DR Jr, Slavin J, Sellers TA, Folsom AR. Carbohydrates, dietary fiber, and incident type 2 diabetes in older women. American Journal of Clinical Nutrition 2000;71(4):921–30.
Montonen J, Knekt P, Jarvinen R, Aromaa A, Reunanen A. Whole-grain and fiber intake and the incidence of type 2 diabetes. American Journal of Clinical Nutrition 2003;77(3):622–9.
Monzillo LU, Hamdy O. Evaluation of insulin sensitivity in clinical practice and in research settings. Nutrion Reviews 2003;61(12):397–412.
Murtaugh MA, Jacobs DR Jr, Jacob B, Steffen LM, Marquart L. Epidemiological support for the protection of whole grains against diabetes. Proceedings of the Nutrition Society 2003;62(1):143–9.
National Diabetes Data Group. Classification and diagnosis of diabetes mellitus and other categories of glucose intolerance. Diabetes 1979;28:1039–57.
Pereira MA, Jacobs DR, Jr., Pins JJ, Raatz SK, Gross MD, Slavin JL et al. Effect of whole grains on insulin sensitivity in overweight hyperinsulinemic adults. American Journal of Clinical Nutrition 2002; 75(5):848–55.
Robertson RP, Harmon J, Tran PO, Poitout V. Beta-cell glucose toxicity, lipotoxicity, and chronic oxidative stress in type 2 diabetes. Diabetes 2004;53 Suppl 1:s119–24.
Salmeron J, Ascherio A, Rimm EB, Colditz GA, Spiegelman D, Jenkins DJ, et al. Dietary fiber, glycemic load, and risk of niddm in men. Diabetes Care 1997b;20(4):545–50.
Salmeron J, Manson JE, Stampfer MJ, Colditz GA, Wing AL, Willett WC. Dietary fiber, glycemic load, and risk of non-insulin-dependent diabetes mellitus in women. jama:
the Journal of the American Medical Association 1997a;277(6):472–7.
Schulz KF, Chalmers I, Hayes RJ, Altman DG. Empirical evidence of bias. Dimensions of methodological quality associated with estimates of treatment effects in controlled trials. jama: The Journal of the American Medical Association 1995;273:408–12.
Schulze MB, Liu S, Rimm EB, Manson JE, Willett WC, Hu FB. Glycemic index, glycemic load, and dietary fiber intake and incidence of type 2 diabetes in younger and middle-aged women. American Journal of Clinical Nutrition 2004;80(2):348–56.
Sjoholm A, Nystrom T. Endothelial inflammation in insulin resistance. Lancet 2005;365(9459):610–2.
Slavin J. Why whole grains are protective: biological mechanisms. Proceedings of the Nutrition Society 2003;62(1):129–34.
Sloth B, Krog-Mikkelsen I, Flint A, Tetens I, Bjorck I, Vinoy S, et al. No difference in body weight decrease between a low-glycemic-index and a high-glycemic-index diet but reduced ldl cholesterol after 10-wk ad libitum intake of the low-glycemic-index diet.
American Journal of Clinical Nutrition 2004;80(2):337–47.
Steffen LM, Jacobs DR Jr, Murtaugh MA, Moran A, Steinberger J, Hong CP, et al. Whole grain intake is associated with lower body mass and greater insulin sensitivity among adolescents. American Journal of Epidemiology 2003;158(3):243–50.
1
Stevens J, Ahn K, Juhaeri, Houston D, Steffan L, Couper D. Dietary fiber intake and glycemic index and incidence of diabetes in African-American and white adults: the aric study. Diabetes Care 2002;25 (10):1715–21.
Trowell H. Dietary-fiber hypothesis of the aetiology of diabetes mellitus. Diabetes 1975;24:762–5.
Unwin N, Shaw J, Zimmet P, Alberti KG. Impaired glucose tolerance and impaired fasting glycaemia: the current status on definition and intervention. Diabetic Medicine 2002;19(9):708–23.
us Food and Drug Administration. Whole-grain foods authoritative statement claim notification. Docket No.99p-2209 2005.
us Food and Drug Administration. Whole-grain label statements. Draft Guidelines.
ww.cfsan.fda.gov/~dms/flgragui.html 2006.
Vinceti M, Rovesti S, Pacchinoi C, Ropa G, Roncaia R, Benedetti P, et al. Diet as a risk factor for abnormal glucose tolerance in subjects with and without family history of diabetes mellitus. Diabetes, Nutrition and Metabolism 1994;7:21–8.
Weickert MO, Mohlig M, Schofl C, Arafat AM, Otto B, Viehoff H, et al. Cereal fiber improves whole-body insulin sensitivity in overweight and obese women. Diabetes Care 2006;29:775–80.
Willett W, Manson J, Liu S. Glycemic index, glycemic load, and risk of type 2 diabetes.
American Journal of Clinical Nutrition 2002;76 (1):274s–80s.
Wolever TM, Mehling C. High-carbohydrate-low-glycaemic index dietary advice improves glucose disposition index in subjects with impaired glucose tolerance. British Journal of Nutrition 2002;87(5):477–87.
Wolever TM, Mehling C. Long-term effect of varying the source or amount of dietary carbohydrate on postprandial plasma glucose, insulin, triacylglycerol, and free fatty acid concentrations in subjects with impaired glucose tolerance. American Journal of Clinical Nutrition 2003;77(3):612–21.
World Health Organization Expert Committee on Diabetes Mellitus. Second report.
Technical Report Series 646. Geneva: World Health Organisation, 1980.
World Health Organization. Definition, Diagnosis and Classification of Diabetes Mellitus and its Complications. Report of a who Consultation. Part 1: Diagnosis and Classification of Diabetes Mellitus. Geneva: World Health Organisation, 1999.
World Health Organization. Diabetes Mellitus: Report of a who Study Group. Technical Report Series No 727. Geneva: World Health Organisation,1985.
2
Appendix